Destacking device for ice-cream cones

ABSTRACT

A destacking device for rolled cone-like structures with or without sleeves, and in particular for ice-cream wafer cones, has at least one gripper for the cones, with the jaws of the gripper that come into contact with the cones being made of an elastic material that conforms to the shape of the cone-like structures.

FIELD OF THE INVENTION

The invention relates to a destacking device, with or without sleevesfor handling rolled cone-like structures, in particular for ice-creamcones, wherein the device has a gripper system for the cones.

BACKGROUND OF THE INVENTION

A destacking device of the type mentioned in the introduction isrequired, in particular, for ice-cream production in which conicallyrolled comets or ice-cream wafers (referred to herein below as “cones”for short) are filled, in an ice-cream-filling machine, with the flavorsof ice-cream envisaged therefore and are provided with suitablepackaging. Known ice-cream-filling machines operate cyclically, in whichcase so-called trays each with six to twelve holders for cones areprovided transversely to the running direction of the ice-cream-fillingmachine. The trays are processed simultaneously in one operation overthe width of the six to twelve holders. In this case, the holders of atray are first filled in each case with a conical wafer which isprovided to receive and package the portion of ice cream which is to beproduced. Six to twelve wafer cones then have to be carefully positionedat the same time in the conical packaging units. A chain conveyor thenintermittently transports the tray with the six to twelve wafer conesand processes it further, in particular to fill the cones with one ormore layers of the same or different flavors of ice-cream and thenprovides it with a closure cover.

Destacking devices are required for the abovementioned positioning ofcones in the holders of a tray. Stacks of wafer cones inserted oneinside the other are introduced manually in each case into the magazinesof the destacking machine. From each stack, the lowermost cone then hasto be separated and set down as carefully as possible in the associatedholder of the tray which is to be filled. The performance requirementsare at least around 30 to 60 cycles per minute and a reject rate(breakage) of less than or equal to one per thousand. Furthermore, thedestacking device has to be capable of processing relatively largetolerances of the cones since these products are products made ofnatural ingredients which can also swell as a result of moistureabsorption. For a cone top outer diameter of 42 mm, tolerances of ±2 mmtypically are possible (with a cone length of approximately 105 mm).

As the cones are very fragile, the above-mentioned requirements are verydifficult to achieve. Prior-art destacking devices available in thetrade, for example, as described in U.S. Pat. No. 3,923,200, operatewith rigid metallic grippers, which may comprise holding pins thatretain the stack of cones and allow the lowermost end cone to drop whenthe tray holder is located beneath it. The gripping jaws are usuallymade of metal and protected by a soft material. In addition, the jawshave a small surface in contact with the wafer and they are not providedwith a wafer or conical shape. In addition, they can present a hygienicrisk. Also, the dropping action here results in a relatively high rejectrate. Furthermore, there are problems with the centering of the cones inthe holders. The motion of the grips is generally rotational and themechanical assembly is rather complicated.

An alternative to rigid metallic jaws is proposed for Example inWO99/44479, which relates to a magazine for a dispenser for crispfragile containers which comprises a tube with an elastically resilientmembrane which is placed inside and whose internal volume is variablebetween a first position where it gently holds a wafer stack and asecond position where it allows the free passage of the wafers throughthe tube for dispensing by blowing air between the tube and themembrane. From there, the wafers are taken over by jaws provided withresilient elements. This mechanism is of medium complexity and thereject rate is less.

In view of these disadvantages, improvements in such devices are desiredand some particularly useful improvements are disclosed by the presentinvention.

SUMMARY OF THE INVENTION

The present invention preferably to an improvement in a destackingdevice that includes at least one gripper having a pair of jaws forhandling a stack of rolled fragile structures, such as wafer cones forreceiving ice cream or similar confectioneries. This improvementcomprises making at least the portion of the jaws of the gripper thatcome into contact with the structures of an elastic material so that thestructures can be handled and moved at high cycle rates with little orno breakage.

In a preferred embodiment, the jaws are formed essentially from asilicone or polyurethane material. Also, the jaws are preferablyconfigured and adapted to conform to the structures or to the stack ofsuch structures. Generally, the jaws have two lips that run parallel ina longitudinal direction and are arranged in a V-shaped mannertransversely to the longitudinal direction, and are fastened in aneasily exchangeable manner on a carrier.

In this device, at least one gripper is an individual gripper of amoveable design that is configured and operatively associated with thedevice to separate an end structure from the stack of such structuresand move it to a discharge location. Also, at least one gripper is astack gripper that grips the structures of the stack of structuresexcept for the end structure. For optimum operation, the individualgripper and the stack gripper are connected to control means which isconfigured to cause the grippers to execute the following steps:

-   -   a) retaining the stack by the stack gripper and retaining an end        structure of the stack by the individual gripper;    -   b) moving the individual gripper in order to separate the end        structure as an individual structure from the stack and to        transport it to a discharge location;    -   c) opening the individual gripper in order to set down the        individual structure at the discharge location;    -   d) closing the individual gripper and moving it back to the        stack;    -   e) opening the stack gripper in order to allow the stack to move        further by one structure;    -   f) closing the stack gripper in order to retain the stack;    -   g) repeating steps a) to f), as necessary to remove all        structures from the stack.

The destacking device also can include at least one nozzle which isdirected onto an end of the stack and has a gas-supply line which expelsa gas stream which assists the separation of the end structure from thestack.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained by way of example hereinbelow with the aid ofthe figures, in which:

FIG. 1 shows a front view of a destacking device for cones (ice-creamwafers);

FIG. 2 shows a side view of the grippers of a destacking deviceaccording to the invention;

FIG. 3 shows a section along line III-III from FIG. 2 with a plan viewof the individual gripper.

FIG. 4 shows a perspective view of an upper jaw and

FIG. 5 shows a perspective view of a lower jaw.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention now provides an improved destacking device forrolled ice-cream cones with or without sleeves, in particular forice-cream wafers, which, while maintaining higher cycle rates of atleast 60 cycles per minute, causes only very little breakage of thecones during handling and movement. In addition, the destacking deviceis preferably intended to achieve good centering of the cones at theirdischarge location.

The destacking device according to the invention for rolled ice-creamcones has at least one gripper for the cones. A gripper has, bydefinition, two or more jaws, which can be moved relative to one anotherand, by moving together, can grip an article which is located betweenthem. The destacking device is characterized in that the jaws of thegripper, which come into contact with the cones be made of or consist ofan elastic material.

The elastic, i.e. compliant, design of the jaws of the gripper makes itpossible to grip the ice-cream cones both securely and carefully. Thisincreases the precision of the cone guidance, while, at the same time,fewer cones end up breaking. The elasticity of the material here shouldbe selected to be suitable for the cones which are to be processed andthe fragility thereof. The elasticity should be high enough (i.e. theelasticity constant should be low enough) for the maximum elastic forceswhich occur when the jaws of the gripper are moved together into theclosed position, in the case of all cone sizes which are possible withinthe tolerance range, to remain below the breaking limit of the cones. Onthe other hand, the jaws should not be too flexible, this ensuring thatthe cones are fixed and positioned as precisely as possible in thegripper.

The most preferred materials for use in producing the jaws of thegrippers are those that are hygienically compatible with the productbeing gripped. In particular, silicones or polyurethanes are preferablyused for producing the jaws of the gripper. Furthermore, it is preferredif the jaws are profiled or shaped to correspond to the shape of thecones and/or the shape of the stack. This ensures secure gripping of thecones or of the stack and distribution of the contact force over thelargest possible surface area, with the result that destructive stresspeaks cannot occur at any point. In the case of the jaws with singleblock molding of elastic material, this will improve also the hygienicdesign of the equipment.

According to a preferred configuration, the jaws each have two lipswhich run parallel in their longitudinal direction and are located at anangle, i.e. arranged in a v-shaped manner, transversely to theirlongitudinal direction, with the result that it is possible for saidjaws, by way of these lips, to position themselves against a cone oragainst a stack and to clamp the latter in carefully between the lips.

The jaws of the grippers are preferably fastened in an easilyexchangeable manner on a carrier, as a result that, in the event ofpossible damage or wear, they can easily be replaced or, if the size ofthe processed cones changes, exchanged.

According to a development of the destacking device, the lattercontains, as gripper, an individual gripper, which can be moved as awhole such that it can separate an end cone from the stack of cones andmove it to a predetermined discharge location. In contrast to the knowndestacking devices for ice-cream wafers, the end cone, followingseparation from the stack, rather than simply being allowed to drop inthe direction of the discharge location, is guided there in a definedmanner, and set down at the target location, with the aid of theindividual gripper. This reduces the breakage produced when the conedrops and, at the same time, results in better seating and in centeringof the separated cone at the discharge location.

According to another development of the destacking device, the latterhas, as gripper, a stack gripper which can grip the cones of a stack,apart from the end cone. Such a stack gripper can thus fix the stackwhich is located in the magazine of the device, the elastic design ofthe jaws of the stack gripper, despite the relatively large dimensionaltolerances of the cones, allowing essentially all the cones to begripped at the same time.

The destacking device provided with an individual gripper and a stackgripper may, furthermore, be connected to a control means, which is setup in order to make the two grippers execute the following steps:

-   -   a) retaining the stack of cones, with the exception of the end        cone, by the stack gripper and retaining the end cone of the        stack by the individual gripper;    -   b) moving the individual gripper in order to separate the end        cone as an individual cone from the stack and to transport it to        a predetermined discharge location;    -   c) opening the individual gripper in order to set down the        individual cone at the discharge location;    -   d) closing the individual gripper and moving it back to the        stack;    -   e) opening the stack gripper in order to allow the stack to move        further by one cone;    -   f) closing the stack gripper in order to retain the stack in the        new position;    -   g) repeating steps a) to f).

Such a destacking device allows the cyclic operation which is requiredof known ice-cream-filling machines, the interaction of the stackgripper and individual gripper resulting in extremely careful and, atthe same time, precise handling of the cones.

The device according to the invention, furthermore, may be developed inthat it contains at least one nozzle which is directed towards the endof the stack and has a gas-supply line which can expel a gas stream(preferably compressed air at approximately 3 bar) which assists theseparation of the end cone from the stack.

FIG. 1 shows a front view of part of a destacking device 1 for conicalice-cream wafers (referred to herein below as “cones”). In thisdestacking device, a stack 2 of cones, which have been inserted oneinside the other is guided in a magazine which is formed from threevertical rods arranged in a triangle. The cones are to be inserted intothe holders 5 of a tray 6. The holders here have already been filledwith conical paper packaging units 4 beforehand.

FIG. 2 shows a side view of the grippers 10, 11, which are essential tothe invention, of the destacking device 1 in an arrangement in whichthey are ready for operation, the rest of the parts of the device havingbeen left out. It is possible to see a top, stack gripper 11 with twomirror-inverted gripper arms, which can be moved relative to one anotherin the horizontal direction (double arrow) in order to be able toaccommodate and retain a stack of cones (not illustrated) between them.The upper jaws 9 (FIG. 4) of the stack gripper 11 which come intocontact with the stack are formed by elongate, profiled elements made ofan elastic polymer material, for example silicone or polyurethane. Atthe bottom of the upper jaw, as shown in FIG. 4, there is a reduction ofthe diameter to obtain good separation of the last cone without the riskof picking up two cones at the same time.

Located beneath the stack gripper 11 is an individual gripper 10, whichdiffers from the stack gripper 11 essentially in that its verticalextent is very much shorter, and in that its elastic jaws 8 (FIG. 5) arearranged obliquely and such that they taper conically in relation to oneanother in accordance with the cone angle of the cones. By means of thejaws 8, the individual gripper 10 can grip the lowermost, end cone 3 ofa stack and separate it from the rest of the stack since (only) thislowermost cone 3 is not secured by the stack gripper 11.

The jaws 8 and 9 can be moved apart from one another in each case, forexample, via a pneumatic spreading mechanism, with the result that thewafers can be either packaged or released. This can take place, inparticular, via universal-jointed rods, which are fastened on apneumatic piston.

FIG. 3 illustrates the individual gripper 10 in a plan view (lineIII-III from FIG. 2). The profiled jaws 8, which are adapted to theshape of an ice-cream cone 3, are clearly visible here. The jaws 8 eachhave two lips, which are located at an angle, in a V-shaped manner, inrelation to one another and can be deformed elastically in the outwarddirection, in order to compensate for tolerances of the cones 3. Theelasticity and flexibility of the material of the jaws 8 cause thelatter to engage in optimum fashion in the wafer pattern of the cones 3.As a result of their elasticity, adherence and good ability to fitclosely, coordinated with the cones 3, the jaws 8 and 9 allow the cones3 to be gripped securely without slippage and without being broken byexcessive forces.

It can also be seen from FIG. 3 that the jaws 8 are clamped on a metalrail 12, which is curved in undulating fashion and, for its part, isfastened on the rest of the arm structure by means of a screw 7. It isthus possible for the jaws to be easily adjusted and, if required, alsoexchanged.

An operating cycle of the destacking device I proceeds essentially asfollows:

A stack 2 of cones is located in the vertical magazine. In order toperform a reset function, first of all the jaws 9 of the stack gripper11 are opened, while the individual gripper 10 is closed. The stackgripper 11 is activated such that the stack 2 of the wafer cones issecured, apart from the lowermost, end cone 3. This concludes the resetoperation.

The actual lowering operation of the end cone 3 is triggered, via thechain with the holders 5, at the pulse of a proximity switch, if theholders 5 are in the appropriate position and remain there. At thismoment, the individual gripper 10 moves downwards, with the result thatthe separated cone 3 is conveyed to a level just above the holder 5 ofthe tray 6. The individual gripper 10 is then opened by virtue of thejaws 8 being moved apart from one another, and the cone 3 drops a shortdistance, typically of 40 to 50 mm, into the holder. The ice-cream coneis additionally braked by the air cushion, which is produced in theconical packaging just before the end position is reached. Since thedropping distance is very small in relation to the prior-art droppingheight, there is barely any breakage, and the cones, in addition, areseated with good centering in the holders.

Following opening of the individual gripper 10, the latter is guidedupwards again to the bottom end of the stack 2 and is closed again byvirtue of the jaws 8 being moved together. The stack gripper 11 is thenopened some way by virtue of the jaws 9 being moved apart from oneanother, with the result that the stack 2 can slip down and the cone,which is now at the end can pass into the individual gripper 10. Theabove-described operation can then be executed anew. This means that therequired cycle rates of 60/min can be reached without difficulty, itbeing possible for the operation to proceed with overall time control,triggered by the holder chain.

In order to assist the separation of the cones from the stack 2, it isfurther possible for two nozzles (not illustrated) to blow an air streamlaterally from above into the cone 3 which is to be separated, in order,for example, to prevent the situation where the cone located there aboveis also withdrawn, despite the retaining forces of the stack gripper 11,or where the separated cone slides off the individual gripper again.

Exchanging the jaws 8, 9 and/or the grippers 10, 11 as a whole allowsthe destacking device to be easily adapted, if required, to otherdimensions of cone.

1. In a destacking device that includes at least one gripper having a pair of jaws for handling a stack of rolled fragile structures with or without sleeves, the improvement which comprises making at least the portion of the jaws of the gripper that come into contact with the structures of an elastic material so that the structures can be handled and moved at high cycle rates with little or no breakage.
 2. The destacking device of claim 1, wherein the jaws are formed essentially from a silicone or polyurethane material.
 3. The destacking device of claim 1, wherein the jaws are configured and adapted to conform to the structures or to the stack of such structures.
 4. The destacking device of claim 1, wherein the jaws have two lips which run parallel in a longitudinal direction and are arranged in a V-shaped manner transversely to the longitudinal direction.
 5. The destacking device of claim 1, wherein the jaws are fastened in an easily exchangeable manner on a carrier.
 6. The destacking device of claim 1, wherein at least one gripper is an individual gripper of a moveable design that is configured and operatively associated with the device to separate an end structure from the stack of such structures and move it to a discharge location.
 7. The destacking device of claim 6, wherein at least one gripper is a stack gripper that grips the structures of the stack of structures except for the end structure.
 8. The destacking device of claim 7, wherein the individual gripper and the stack gripper are connected to control means which is configured to cause the grippers to execute the following steps: a) retaining the stack by the stack gripper and retaining an end structure of the stack by the individual gripper; b) moving the individual gripper in order to separate the end structure as an individual structure from the stack and to transport it to a discharge location; c) opening the individual gripper in order to set down the individual structure at the discharge location; d) closing the individual gripper and moving it back to the stack; e) opening the stack gripper in order to allow the stack to move further by one structure; f) closing the stack gripper in order to retain the stack; g) repeating steps a) to f), as necessary to remove all structures from the stack.
 9. The destacking device of claim 1, which includes at least one nozzle which is directed onto an end of the stack and has a gas-supply line which expels a gas stream which assists the separation of the end structure from the stack.
 10. The destacking device of claim 1, wherein the structures are handled and moved at around 60 cycles per minute with a reject or breakage rate that is less than or equal to one structure per thousand structures handled.
 11. The destacking device of claim 1, wherein the structures are wafer cones that are intended to receive ice cream or similar confectioneries. 